1. Field of the Invention
The present invention relates to a device and process for encoding audio data, and in particular to a process for determining encoding parameters for use in MPEG audio encoding.
2. Description of the Related Art
The MPEG-1 audio standard, as described in the International Standards Organization (ISO) document ISO/IEC 11172-3: Information technology—Coding of moving pictures and associated audio for digital storage media at up to about 1.5 Mbps (“the MPEG-1 standard”), defines processes for lossy compression of digital audio and video data. The MPEG-1 standard defines three alternative processes or “layers” for audio compression, providing progressively higher degrees of compression at the expense of increasing complexity. The third layer, referred to as MPEG-1-L3 or MP3, provides an audio compression format widely used in consumer audio applications. The format is based on a psychoacoustic or perceptual model that allows significant levels of data compression (e.g., typically 12:1 for standard compact disk (CD) digital audio data using 16-bit samples sampled at 44.1 kHz), whilst maintaining high quality sound reproduction, as perceived by a human listener. Nevertheless, it remains desirable to provide even higher levels of data compression, yet such improvements in compression are usually attended by an undesirable degradation in perceived sound quality. Accordingly, it is desired to address the above or at least to provide a useful alternative.